As the slivers come out of the drier they are fed through a number of gill boxes. The gill box is the first of a long series of drawing operations. In this, and all the following stages of open drawing, there are always several slivers being combined into one and drawn out until the resulting sliver has about the same or a smaller diameter than the ones fed into the machine. The principle of the gill box is quite simple. Several slivers are fed in between rollers revolving at a comparatively low rate of speed. As they pass through they are flattened out over what is known as a faller. This is armed with very fine close wire teeth which come up through the fibres and the draft is imparted when the wool is taken off the faller by a final pair of rollers which are revolving considerably faster. The sheet of wool which emerges from these rollers is again passed through a funnel and thereby condensed once more into a sliver. This operation is repeated from two to four times, according to the quality of the top desired, and the methods employed by the particular mill.
Gilling the top
Where very coarse long fibred wool is to be worked there is no carding, and the wool is prepared by straightening the fibres into a sliver through a series of gill-boxes.
At some point during the gilling process a slight amount of oil is usually dropped onto the sliver, as this facilitates combing.
4. Combing
Removes Short Fibres
The next operation, namely that of combing, is again simple when viewed as the primitive manufacturing process. The old comber would take a short length of sliver, hang it on a nail by tying one end together and then proceed to comb out the short fibres much as one may comb out the dead short hairs from a dog’s coat. Combing is simply the removal from the sliver of the short fibres which would not spin properly. These short fibres are known as noils and are the waste product of top-making. The top is a continuous untwisted strand of long wool fibres made parallel by the comb. (By long fibres we mean fibres which are relatively long. Some tops consist of fibres less than an inch and a half in length. In this case, which is very infrequent, the noil would be even shorter.)
The Noble Comb